True statement regarding first order kinetics is
**Core Concept**
First-order kinetics is a type of pharmacokinetic process where the rate of elimination of a drug is directly proportional to its plasma concentration. This means that as the concentration of the drug increases or decreases, the rate of elimination also increases or decreases proportionally.
**Why the Correct Answer is Right**
The correct answer is related to the principle that the half-life of a drug is constant in first-order kinetics. This is because the rate of elimination is directly proportional to the plasma concentration, resulting in a constant half-life that is independent of the initial dose or concentration. In first-order kinetics, the elimination rate is constant, and the half-life remains the same regardless of the initial concentration. This is in contrast to zero-order kinetics, where the half-life is dependent on the initial dose or concentration.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it contradicts the fundamental principle of first-order kinetics, where the rate of elimination is directly proportional to the plasma concentration.
**Option B:** This option is incorrect because it is a characteristic of zero-order kinetics, where the rate of elimination is constant and independent of the plasma concentration.
**Option C:** This option is incorrect because it is a characteristic of first-order kinetics, but it is not the correct answer regarding the statement about first-order kinetics.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that first-order kinetics is a common phenomenon in many drugs, and understanding this concept is crucial for predicting drug concentrations and optimizing dosing regimens.
**Correct Answer: C. The half-life of a drug in first-order kinetics is constant and independent of the initial dose.**